Downlink CQI Feedback Using Decoded Code Block Sparsity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In MIMO communication systems, the reported Channel Quality Indicator (CQI) often differs from the actual downlink channel CQI, leading to inaccurate calculations and prolonged adjustment times in outer loop link adaptation, especially when the estimated SINR differs significantly from the actual SINR, making the adjustment process sensitive to errors and inefficient.
Innovation Solution
A communication method where the terminal device sends indication information based on the quantity or proportion of non-zero elements in the decoded sequence related to the check matrix, allowing the network device to adjust the CQI more accurately and efficiently, thereby improving CQI adjustment efficiency and selecting appropriate configuration parameters for downlink transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If outer loop link adaptation (OLLA) is used to adjust SINR based on ACK/NACK feedback, then CQI matching with actual transmission link is achieved, but adjustment time is prolonged especially when estimated SINR differs greatly from actual SINR
Solution Approach 1:
The patent applies preliminary action by using the decoded sequence from the current transmission to directly adjust the CQI for the next transmission, rather than waiting for ACK/NACK feedback. The terminal device performs channel decoding on the downlink data to obtain a decoded sequence, then uses this sequence to determine adjustment information that is fed back to the network device for immediate CQI adjustment, bypassing the time-consuming ACK/NACK round-trip process.
2Reliability
If OLLA adjusts SINR based on ACK/NACK feedback, then CQI is matched with actual link, but the adjustment process is sensitive to errors and time is greatly prolonged once an error occurs
Solution Approach 1:
The patent implements a new feedback mechanism where the terminal device sends adjustment information based on the decoded sequence to the network device. This feedback contains information about the quantity of non-zero elements or the quantity of zero elements in the decoded sequence, which directly indicates the accuracy of the decoding process and enables more reliable and faster CQI adjustment without the error sensitivity of traditional ACK/NACK-based OLLA.
3Productivity
If terminal device measures downlink channel based on CSI-RS to determine CQI, then CQI calculation is performed, but CQI is inaccurately calculated due to difference between assumed case and actual transmission case
Solution Approach 1:
The patent applies self-service by having the terminal device use its own decoded sequence from actual downlink data transmission to generate adjustment information, rather than relying on external CSI-RS measurements and assumptions. The decoded sequence inherently reflects the actual transmission conditions including channel characteristics, interference, and noise, enabling the terminal to self-correct CQI based on real performance data rather than theoretical assumptions.
Data Source
AI summary
Embodiments of this application disclose a communication method and a related apparatus. The method includes: receiving downlink data from a network device, where the downlink data corresponds to one or more code blocks CBs; determining, based on the downlink data, a decoded sequence obtained by performing channel decoding on the downlink data; and sending indication information to the network device, where the indication information indicates first information, the first information is determined based on a quantity of non-zero elements or a quantity of zero elements included in first data, the first data is determined based on the decoded sequence, one piece of first data corresponds to one CB, the first data is related to C and H.